A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star or falling star; astronomers call the brightest examples “bolides”. Once it settles on the larger body’s surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
Meteorites that are recovered after being observed as they transit the atmosphere and impact the Earth are called meteorite falls. All others are known as meteorite finds. As of August 2018, there were about 1,412 witnessed falls that have specimens in the world’s collections. As of 2018, there are more than 59,200 well-documented meteorite finds.
Moldavite (Czech: Vltavín) is a forest green, olive green or blue greenish vitreous silica projectile rock formed by a meteorite impact probably in southern Germany (Nördlinger Ries Crater) that occurred about 15 million years ago. It is a type of tektite.
Tektites (from Greek τηκτός tēktós, “molten”) are gravel-sized bodies composed of black, green, brown, or gray natural glass formed from terrestrial debris ejected during meteorite impacts. The term was coined by Austrian geologist Franz Eduard Suess (1867–1941), son of Eduard Suess. They generally range in size from millimeters to centimeters. Millimeter-scale tektites are known as microtektites.